PAL20X8 PAL DESIGN SPECIFICATION P7009 (SN54/74LS380) BIRKNER/KAZMI/BLASCO 02/16/81 MULTIFUNCTION OCTAL REGISTER MMI SUNNYVALE, CALIFORNIA CLK /LD D0 D1 D2 D3 D4 D5 D6 D7 POL GND /OC /PR Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 /CLR VCC /Q0 := CLR ;CLEAR + /CLR*/PR*/LD*/Q0 ;HOLD :+: /CLR*/PR* LD* POL*/D0 ;LOAD D0 (TRUE) + /CLR*/PR* LD*/POL* D0 ;LOAD /D0 (COMP) /Q1 := CLR ;CLEAR + /CLR*/PR*/LD*/Q1 ;HOLD :+: /CLR*/PR* LD* POL*/D1 ;LOAD D1 (TRUE) + /CLR*/PR* LD*/POL* D1 ;LOAD /D1 (COMP) /Q2 := CLR ;CLEAR + /CLR*/PR*/LD*/Q2 ;HOLD :+: /CLR*/PR* LD* POL*/D2 ;LOAD D2 (TRUE) + /CLR*/PR* LD*/POL* D2 ;LOAD /D2 (COMP) /Q3 := CLR ;CLEAR + /CLR*/PR*/LD*/Q3 ;HOLD :+: /CLR*/PR* LD* POL*/D3 ;LOAD D3 (TRUE) + /CLR*/PR* LD*/POL* D3 ;LOAD /D3 (COMP) /Q4 := CLR ;CLEAR + /CLR*/PR*/LD*/Q4 ;HOLD :+: /CLR*/PR* LD* POL*/D4 ;LOAD D4 (TRUE) + /CLR*/PR* LD*/POL* D4 ;LOAD /D4 (COMP) /Q5 := CLR ;CLEAR + /CLR*/PR*/LD*/Q5 ;HOLD :+: /CLR*/PR* LD* POL*/D5 ;LOAD D5 (TRUE) + /CLR*/PR* LD*/POL* D5 ;LOAD /D5 (COMP) /Q6 := CLR ;CLEAR + /CLR*/PR*/LD*/Q6 ;HOLD :+: /CLR*/PR* LD* POL*/D6 ;LOAD D6 (TRUE) + /CLR*/PR* LD*/POL* D6 ;LOAD /D6 (COMP) /Q7 := CLR ;CLEAR + /CLR*/PR*/LD*/Q7 ;HOLD :+: /CLR*/PR* LD* POL*/D7 ;LOAD D7 (TRUE) + /CLR*/PR* LD*/POL* D7 ;LOAD /D7 (COMP) FUNCTION TABLE D7 D6 D5 D4 D3 D2 D1 D0 /CLR /PR /LD POL CLK /OC Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 ; INPUTS CONTROL OUTPUTS COMMENTS ; D7----D0 /CLR /PR /LD POL CLK /OC Q7----Q0 ------------------------------------------------------------------------------ ;CLEAR AND PRESET TESTS HHHHHHHH L L L H C L LLLLLLLL CLEAR (OVERRIDES PRESET/LOAD) LLLLLLLL H L L H C L HHHHHHHH PRESET (OVERRIDES LOAD) LLLLLLLL L L L L C L LLLLLLLL CLEAR (POL=L) HHHHHHHH H L L L C L HHHHHHHH PRESET (POL=L) ;LOAD DATA - WALKING ZEROES (TRUE DATA) HHHHHHHL H H L H C L HHHHHHHL LOAD HEX(FE) HHHHHHLH H H L H C L HHHHHHLH LOAD HEX(FD) HHHHHLHH H H L H C L HHHHHLHH LOAD HEX(FB) HHHHLHHH H H L H C L HHHHLHHH LOAD HEX(F7) HHHLHHHH H H L H C L HHHLHHHH LOAD HEX(EF) HHLHHHHH H H L H C L HHLHHHHH LOAD HEX(DF) HLHHHHHH H H L H C L HLHHHHHH LOAD HEX(BF) LHHHHHHH H H L H C L LHHHHHHH LOAD HEX(7F) HHHHHHHH H H L H C L HHHHHHHH LOAD HEX(FF) ;LOAD DATA - WALKING ONES (TRUE DATA) LLLLLLLH H H L H C L LLLLLLLH LOAD HEX(01) LLLLLLHL H H L H C L LLLLLLHL LOAD HEX(02) LLLLLHLL H H L H C L LLLLLHLL LOAD HEX(04) LLLLHLLL H H L H C L LLLLHLLL LOAD HEX(08) LLLHLLLL H H L H C L LLLHLLLL LOAD HEX(10) LLHLLLLL H H L H C L LLHLLLLL LOAD HEX(20) LHLLLLLL H H L H C L LHLLLLLL LOAD HEX(40) HLLLLLLL H H L H C L HLLLLLLL LOAD HEX(80) LLLLLLLL H H L H C L LLLLLLLL LOAD HEX(00) ;LOAD DATA - WALKING ONES (COMP DATA) WITH HOLD TESTS LLLLLLLL H H H L C L LLLLLLLL HOLD LLLLLLLL H H L L C L HHHHHHHH LOAD HEX(00) (COMP) LLLLLLLL H H H H C L HHHHHHHH HOLD LLLLLLLH H H L L C L HHHHHHHL LOAD HEX(01) (COMP) LLLLLLLL H H H L C L HHHHHHHL HOLD LLLLLLHL H H L L C L HHHHHHLH LOAD HEX(02) (COMP) HHHHHHHH H H H H C L HHHHHHLH HOLD LLLLLHLL H H L L C L HHHHHLHH LOAD HEX(04) (COMP) LLLLLLLL H H H L C L HHHHHLHH HOLD LLLLHLLL H H L L C L HHHHLHHH LOAD HEX(08) (COMP) HHHHHHHH H H H H C L HHHHLHHH HOLD LLLHLLLL H H L L C L HHHLHHHH LOAD HEX(10) (COMP) LLLLLLLL H H H L C L HHHLHHHH HOLD LLHLLLLL H H L L C L HHLHHHHH LOAD HEX(20) (COMP) HHHHHHHH H H H H C L HHLHHHHH HOLD LHLLLLLL H H L L C L HLHHHHHH LOAD HEX(40) (COMP) LLLLLLLL H H H L C L HLHHHHHH HOLD HLLLLLLL H H L L C L LHHHHHHH LOAD HEX(80) (COMP) HHHHHHHH H H H H C L LHHHHHHH HOLD LLLLLLLL H H L L C L HHHHHHHH LOAD HEX(00) (COMP) XXXXXXXX X X X X X H ZZZZZZZZ TEST HI-Z ------------------------------------------------------------------------------ DESCRIPTION THIS IS AN 8-BIT SYNCHRONOUS REGISTER WITH PARALLEL LOAD, LOAD COMPLEMENT, PRESET, CLEAR, AND HOLD CAPABILITIES. FOUR CONTROL INPUTS (/LD,POL,/CLR,/PR) PROVIDE ONE OF FOUR OPERATIONS WHICH OCCUR SYNCHRONOUSLY WITH THE CLOCK (CLK). THE LOAD OPERATION LOADS THE INPUTS (D7-D0) INTO THE OUTPUT REGISTER (Q7-Q0), WHEN POL=H OR LOADS THE COMPLEMENT OF THE INPUTS WHEN POL=L. THE CLEAR (/CLR) OPERATION RESETS THE OUTPUT REGISTERS TO ALL LOWS. THE PRESET (/PR) OPERATION PRESETS THE OUTPUT REGISTERS TO ALL HIGHS. THE HOLD OPERATION HOLDS THE PREVIOUS VALUE REGARDLESS OF CLOCK TRANSITIONS. CLEAR OVERRIDES PRESET, PRESET OVERRIDES LOAD, AND LOAD OVERRIDES HOLD. THESE OPERATIONS ARE EXERCISED IN THE FUNCTION TABLE AND SUMMARIZED IN THE OPERATIONS TABLE: /OC CLK /CLR /PR /LD POL D7-D0 Q7-Q0 OPERATION --------------------------------------------------------- H X X X X X X Z HI-Z L C L X X X X L CLEAR L C H L X X X H PRESET L C H H H X X Q HOLD L C H H L H D D LOAD TRUE L C H H L L D /D LOAD COMP ---------------------------------------------------------